A Universal file format is PDF file because it can open many devices like Smartphones, Tablets etc. Therefore this Relevance features make it template files for any user for send information. You can also lock your PDF files, it avoid able to copy, edit and print the files. But locking PDF files has some good and bad future for you. If you forget the password and not able to retrieve password then what will you do. therefore  some several reasons why you require to edit, print or copy a PDF file but if not able to retrieve your forgotten password there is some steps to Unlock your password.